The characteristic features demonstrated here include an underlying normal sinus mechanism, with normal P waves preceding each QRS, and early or premature QRS complexes that are wide and different from the sinus QRS. Note that the ST-T configuration of the premature complexes is different from the sinus beats,and that there are no premature P waves associated with these complexes.

The significance of isolated premature ventricular complexes is determined by the clinical setting in which they occur.